Surgical procedures using instrument to boundary spacing information extracted from real-time diagnostic scan data

ABSTRACT

Specific embodiments of the invention are directed to improved surgical procedures involving the use of processed non-visual three-dimensional data (i.e. diagnostic scan data) to provide a surgeon with additional guidance (i.e. more than that generally obtained from visual observation of the working area) concerning the distance separating a working end of a surgical instrument and the posterior portion of a target tissue. Separation information may be used to aid the surgeon in minimizing the risk of unintended penetration of adjacent tissue with the working end of the instrument. Some embodiments provide for the visual and/or auditory conveyance of distance information to the surgeon. Additional embodiments provide for overlaying visual representations of selected three-dimensional structure information (e.g. depths of troughs cut into the lens) with the real surface feature images viewed by the surgeon.

RELATED APPLICATIONS

This is a divisional application of U.S. patent non-provisionalapplication Ser. No. 13/169,076 which claims the benefit of U.S.Provisional Patent Application No. 61/358,793, filed Jun. 25, 2010 andis a continuation in part of U.S. patent application Ser. No. 13/164,671filed Jun. 20, 2011 which to turn claims benefit of U.S. ProvisionalPatent Application No. 61/356/150 filed Jun. 18, 2010. These referencedapplications which are hereby incorporated by reference as if set forthin full herein.

FIELD OF THE INVENTION

The present invention relates generally to the field of surgicalprocedures and more particularly to surgical procedures involving nearbyboundary regions where surgical instrument penetration is to beminimized or eliminated (i.e. non-fly zones) and wherein computergenerated feedback concerning separation distance between a surgicalinstrument and such boundaries is automatically calculated and opticalor auditory feedback is presided to the surgeon to aid in theperformance of the surgery. Specific embodiments of the invention relateto the field of ophthalmic surgery and more particularly to the field ofphacoemulsification procedures (e.g. cataract removal procedures)wherein diagnostic scan data is processed to supply useful and timelysurgical information beyond that which is normally available to asurgeon via visual observation.

BACKGROUND OF THE INVENTION

Surgical procedures: (1) involve certain risks to the patient, (2) takea certain time to perform, (3) take a certain experience or skill levelby a surgeon, (4) result in the collateral damage of healthy issue, (5)result in the excess removal of healthy tissue, (6) result in theinadequate removal of unhealthy tissue, (7) result in the failure tofulfill the surgical goal, (8) require prolonged recovery times, (9)result in extended periods of disability, and/or (10) result in the needfor extended therapy. If a surgeon could be provided with moreinformation during the performance of a procedure be provided with thatinformation in a more timely manner, and/or be provided with thatinformation in a more accessible manner, many such procedures could: (1)be performed with less risk to the patient, (2) be performed morequickly, (3) be performed by a surgeon with less experience or skill,(4) result in reduced collateral damage, (5) result in removal of lesshealthy tissue, (6) result in more complete removal of unhealthy tissue,(7) result in higher probability of fulfilling the surgical goal (8)result in less recovery time, (9) result in less disability or shortenedperiods of disability, and/or (10) result in less need for physicaltherapy. A need exists in the surgical arts for a method of providingmore information, proving this additional information in a timelymanner, and/or providing this information in a more accessible manner.

Surgical procedures often involve tissue penetration, manipulation,and/or removal of tissue near a boundary region that is preferably notcrossed or damaged by the surgical instrument during the procedure. Toavoid inadvertently penetrating such boundaries while still completingthe procedure with optimal results may require the procedure to beslowed down while working in these critical areas, require that not alltissue on the working side of the boundary be optimally accessed, orrequire other procedural complexities to exist. A need exists in thesurgical arts for improved procedures and systems for addressing theseissues.

In cataract removal procedures, visual observations and surgicalexperience are used to determine when scoring or cutting the crystallinelens has proceeded to a sufficient depth such that cracking or choppingcan be used to break the lens into smaller pieces. Unfortunately,inadequate information can lead to undercutting or overcutting (e.g.including penetration beyond the posterior portion of capsule). A needexists for an improved surgical procedure and system that reduces therisk for posterior capsule damage.

SUMMARY OF THE INVENTION

is an object of some embodiments of the invention to provide an improvedsurgical procedure wherein the provision of more information to thesurgeon, the more timely provision of the information, and/or the moreaccessible provision of the information results in the procedure beingperformed with less risk to the patient.

It is an object of some embodiments of the invention to provide animproved surgical procedure wherein the provision of more information tothe surgeon, the more timely provision of the information, and/or themore accessible provision of the information results in the procedurebeing performed more quickly

It is an object of some embodiments of the invention to provide animproved surgical procedure wherein the provision of more information tothe surgeon, the more timely provision of the information, and/or themore accessible provision of the information results in the procedurebeing successfully performable by a surgeon with less experience orskill.

It is an object of some embodiments of the invention to provide animproved surgical procedure wherein the provision of more information tothe surgeon, the more timely provision of the information, and/or themore accessible provision of the information results in reducedcollateral damage.

It is an object of some embodiments of the invention to provide animproved surgical procedure wherein the provision of more information tothe surgeon, the more timely provision of the information, and/or themore accessible provision of the information results in the removal ofless healthy tissue.

It is an object of some embodiments of the invention to provide animproved surgical procedure wherein the provision of more information tothe surgeon, the more timely provision of the information and/or themore accessible provision of the information results the more completeremoval of unhealthy tissue.

It is an object of some embodiments of the invention to provide animproved surgical procedure wherein the provision of more information tothe surgeon, the more timely provision of the information, and/or themore accessible provision of the information results in higherprobability of fulfilling the surgical goal.

It is an object of some embodiments of the invention to provide animproved surgical procedure wherein the provision of more information tothe surgeon, the more timely provision of the information, and/or themore accessible provision of the information results in less recoverytime.

It is an object of some embodiments of the invention to provide animproved surgical procedure wherein the provision of more information tothe surgeon, the more timely provision of the information, and/or themore accessible provision of the information results in less disabilityor shortened periods of disability.

It is an object of some embodiments of the invention to provide animproved surgical procedure wherein the provision of more information tothe surgeon, the more timely provision of the information, and/or themore accessible provision of the information results in less need forphysical therapy.

It is an object of some embodiments of the invention to provide animproved method for performing a phacoemulsification procedure.

It is an object of some embodiments of the invention to provide animproved cataract removal procedure.

It is an object of some embodiments of the invention to provide andimproved procedure for placing intraocular lenses.

Other objects and advantages of various embodiments of the inventionwill be apparent to those of skill in the art upon review of theteachings herein. The various embodiments of the invention, set forthexplicitly herein or otherwise ascertained from the teachings herein,may address one or more of the above objects alone or in combination, oralternatively may address some other object ascertained from theteachings herein. It is not necessarily intended that all objects beaddressed by any single embodiment or aspect of the invention eventhough that may be the case with regard to some embodiments or aspects.

A first aspect of the inventions provides a phacoemulsificationprocedure, including; (a) forming at least one opening in the eye toprovide access to the anterior portion of the lens capsule; (b) formingan opening in the anterior region of a lens capsule containing a lens tobe removed; (c) inserting a working end of a phacoemulsificationinstrument through the opening in the anterior region of the lenscapsule; (d) obtaining diagnostic scan data for the lens, the posteriorportion of the capsule and the working end of the phacoemulsificationinstrument; (e) analyzing the diagnostic scan data to obtain aseparation distance between the working end of the phacoemulsificationinstrument and the posterior region of the capsule; (f) operating thephacoemulsification instrument while viewing the lens and the workingend of the phacoemulsification instrument and while receiving separationdistance information from the analysis of the diagnostic scan data andusing the separation distance information in the control of theoperation of the instrument; wherein during the course of the procedure,the diagnostic scan data, the analysis of the data, and the receiving ofthe separation distance information are updated a plurality of times.

Numerous variations of the first aspect of the invention exist and, forexample include: (1) the diagnostic scan data is one of (a) OCT data;(b) MRI data, (c) UBM data, and (d) ultrasound data; (2) the viewing ofthe lens and the working end of the phacoemulsification instrumentoccurs directly; (3) the viewing of the lens and the working end of thephacoemulsification instrument occurs indirectly (e.g. via an imagecaptured by a camera; (4) the data associated with an entire diagnosticscan being analyzed to identify a location of the working end and asurface of the posterior region of the capsule; (5) only a portion ofthe data associated with an entire diagnostic scan is analyzed toidentify a location of the working end and a relevant portion ofposterior region of the capsule; (6) using an image captured by a camerato produce visual image data that is analyzed to at least partiallyidentify a tip location of the working end of the phacoemulsificationinstrument; (7) identifying the posterior region of the capsule using anintensity gradient based technique; (8) identifying the working end ofthe phacoemulsification instrument using intensity gradient basedtechniques; (9) presenting the separation distance information to thesurgeon by and auditory signal; (10) presenting separation distanceinformation to the surgeon by a visual signal presented within the imagefield containing the surgical field of view; (11) updating of capturedand displayed visual images occur a plurality of times per second, forexample 20 or more times per second or even 100 or more times persecond; (12) updating the diagnostic scan data a plurality of times perminute, for example, at a rate of at least once every 10 second, at arate of at least once per second, or even at a rate of 5 or more timesper second; (13) updating the diagnostic scan data upon an indicationfrom the operator; (14) in addition to providing separation distanceinformation, analyzing diagnostic scan data to provide thicknessinformation between an anterior surface of the lens and the posteriorportion of the capsule, for example, along lines that are substantiallyparallel to Z-axis for a plurality of XY locations and wherein in somefurther variations the thickness information may be presented as avisual representation to the surgeon overlaid with the visual imagebeing viewed by the surgeon and it may be updated a plurality of timesper second (e.g. 20 or more times per second); and (15) in addition toproviding separation distance information, analyzing diagnostic scandata and rendering the results of the analysis to proved a visualrepresentation of selected physical structures overlaid with the visualimage that is presented to the surgeon.

Additional variations of the fifth venation of first aspect of theinvention include having the portion of the data that is analyzed beingselected, at least in part, based on a prior known location of theworking end of the phacoemulsification instrument. In some suchvariations the prior known location of the working end of thephacoemulsification instrument includes the location as determined froman immediately preceding analysis. In some such variations the priorknown location is used as a central location of a search volume to beanalyzed.

Additional variations of the sixth variation of the first aspect of theinvention include, for example, (1) using the tip location, at least inpart, in defining an analysis region of the diagnostic scan data and/or(2) using the tip location, at least in part, in defining locations toundergo diagnosis scanning.

Additional variations of the first aspect of the invention are possible.In some such variations separation distance may be determined in avariety of different ways, including, for example: (1) identifying theposterior capsule with a plane that is parallel to the XY plane anddefining the plane has having a first Z value, determining a secondZ-value corresponding to the working end of the instrument, anddetermining the difference of the first and second Z-values; (2)defining a geometric solid (e.g. a sphere) of a desired but smalldimension (e.g. radius) that is centered on the working end of theinstrument, and comparing the geometric solid to the identifiedposterior capsule position to determine if an intersection exists, ifnot, increase the dimension by a desired incremental resolution step andrepeat the intersection comparison, and continue iterations until anintersection is determined whereby a separation distance is determinedto have a value somewhere between the immediately preceding dimensionand the dimension that resulted in intersection; and (3) createprogressively offset capsule surface representations, where each offsetrepresentation has an incremental step size, until the working end isintersected and then use the count of the number of steps and theirrespective spacings, with or without taking into consideration the laststep, to determine the separation distance; (4) assuming that theposterior portion of the capsule has a relatively planar central regionwhich defines an XY plane form which a Z-axis extends toward the moreanterior portions of the eye, and wherein the gap is measured as adistance between the working end and the capsule along a line that issubstantially parallel to the Z-axis; (5).

Further variations of the ninth variation of the first aspect of theinvention include using an auditory signal or signals selected from oneor more of: (1) a series of discrete pulse-like signals that can vary intemporal duration based on a predetermined set of distance ranges; (2) aseries of discrete pulse-like signals that can vary in temporalseparation based on a predetermined set of distance ranges; (3) a signalwhose pitch varies in frequency based on a predetermined set of distanceranges; and (4) a signal that enunciates different sounds, selected fromthe group consisting of numbers, letters, words, or phrases based on apredetermined set of distance ranges.

Further variations of the tenth variation of the first aspect of theinvention include using a visual signal or signals selected from one ormore of: (1) color variations overlaid on the working end of thephacoemulsification instrument based on a predetermined set of distanceranges; (2) a geometric shape (e.g. a circular or elliptical image)centered on the working end of the phacoemulsification instrument basedon a predetermined set of distance ranges; (3) a shape located inproximity to the working end of me phacoemulsification instrumentselected from the group consisting of numbers, letters, words, phrases,or geometric shapes based on a predetermined set of distance ranges; (4)a color in combination with a shape located in proximity to the workingend of the phacoemulsification instrument selected from the groupconsisting of numbers, letters, words, phrases, or geometric shapesbased on a predetermined set of distance ranges; (5) a tinting of aselected portion of the image within the field of view based on apredetermined set of distance ranges; (6) a shape located within thefield of view selected from the group consisting of numbers, letters,words, phrases, or geometric shapes based on a predetermined set ofdistance ranges; and (7) an intensity modulation of a portion of thevisual signal within a field of view based on a predetermined set ofdistance ranges; and (8) the overlaid visual representation and visualimage are aligned with one another using markerless tracking methods.Other variations may, for example, present an auditory signal or signalsin addition to the visual signal or signals which may, for example,include one or more of the further variations of the ninth variation ofthe first aspect of the invention as noted above.

A second aspect of the invention provides a medical procedure forpenetrating, or removing target tissue, to a desired thickness from aposterior or distal boundary of the target tissue without penetratingthe boundary with a working end of a surgical instrument, the procedurecomposing: (a) forming at least one opening in a covering tissue inproximity to the anterior surface of the target tissue to provide accessto said anterior surface of the target tissue; (b) inserting a workingend of surgical instrument through the opening in the cover tissue tocontact the target tissue; (d) obtaining diagnostic scan data for thetarget tissue, the posterior boundary, and the working end of thesurgical instrument; (e) analyzing the diagnostic scan data to obtain aseparation distance between the working end of the surgical instrumentand the posterior boundary region; (f) operating the surgical instrumentwhile viewing the target tissue, the working end of the surgicalinstrument and while receiving separation distance information from theanalysis of the diagnostic scan data and using the separation distanceinformation in controlling or deciding how to control of the surgicalinstrument; wherein during the course of the procedure, the diagnosticscan data, the analysis of the data, and the receiving of the separationdistance information are updated a plurality of times.

A third aspect of the invention provides a diagnostic or therapeuticmedical procedure involving the penetration or removal of target tissuefrom one or more selected target tissue locations or placement of amaterial at one or more selected locations relative to a posterior ordistal boundary of the target tissue without penetrating the boundarywith a working end of surgical instrument, the procedure including: (a)inserting a working end of an instrument into the target tissue; (b)obtaining diagnostic scan data for the target tissue, the posteriorboundary, and the working end of the instrument: (c) analyzing thediagnostic scan data to obtain a separation distance between the workingend of the surgical instrument and the posterior boundary region; and(d) moving and operating the instrument while viewing the target tissue,the working end of the instrument, and while receiving separationdistance information from the analysis of the diagnostic scan data andusing the separation distance information in controlling or deciding howto control of the movement and operating of the instrument; whereinduring the course of the procedure, the diagnostic scan data, theanalysis of the data, and the receiving of the separation distanceinformation are updated a plurality of times.

Numerous variations of the second and third aspects of invention exist.Some such variations provide surgical instruments selected from thegroup consisting of (1) a needle, (2) a probe, (3) forceps, (4) a clamp,(5) scissors, (6) a knife, (7) a spreader, (8) a retractor, (9)tweezers, (10) an delivery cannula, (11) an aspirating cannula, (12) acystotome, (13) a hydrodissector, (14) a hook, (15) a phaco chopper (16)a polisher, (17) a scrapper, (18) a tissue extraction tool, and (19) adeposition tool. Other variations provide the features noted in many ofthe variations of the first aspect of the invention, mutatis mutandis.

Other aspects of the invention will be understood by these of skill inthe art upon review of the teachings herein. Other aspects of theinvention may involve combinations of the above noted aspects of theinvention. These other aspects of the invention may provide variouscombinations of the aspects presented above as well as provide otherconfigurations, structures, functional relationships, and processes thathave not been specifically set forth above.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 provides a block diagram representing selected elements of animproved surgical procedure (e.g. an improved phacoemulsificationprocedure) according to a first embodiment of the invention that focuseson enhancements to using a surgical instrument (e.g. aphacoemulsification instrument) to penetrate or remove tissue (e.g.remove the crystalline lens of the eye) from an anterior surface towarda posterior surface which includes not only the use of visual images ofthe surgical field of view that is available to the surgeon but also ofrepresentations of separation distances of a working end of the surgicalinstrument (e.g. phacoemulsification instrument) relative to a posteriorboundary region defining a non-fly zone (no or limited penetration zone)or posterior portion of tissue to be removed (e.g. relative to ananterior surface of the back wall of the capsule which borders theposterior surface of the lens), wherein the separation distance data isextracted from three-dimensional diagnostic scan data.

Numerous variations of the first embodiment are possible. Some of thosepossibilities are set forth in FIGS. 2A-2C which provide examples ofvarious alternatives that may form part of the procedure of the firstembodiment, such as alternative diagnostic scan data types (FIG. 2A),rendering alternatives (FIG. 2B), and distance calculations includingoptional uses of previously known instrument locations (e.g. working endlocations that were obtained from previously analyzed diagnostic data)and/or capsule locations (FIG. 2C).

FIG. 3 provides a block diagram representing selected steps of a secondembodiment of the invention that is similar to the first embodiment ofthe invention with the exception that rendered information takes theform of a visual representation that is overlaid with real visual images(e.g. of a surgical region or area) are presented to the surgeon.

FIG. 4 provides a block diagram representing selected steps of a thirdembodiment of the invention that is similar to the second embodiment ofthe invention with the exception that in addition to the diagnostic scandata being used to provide information concerning an instrument toboundary separation distance of a working end of the instrument and theposterior boundary or surface or an allowed fly-zone or penetrationzone, the diagnostic scan data is also used to provide informationconcerning remaining thickness of material that is located between theworking end of the instrument and the posterior surface, which thicknessmay be less than the distance as some of the intervening material mayalready have been removed, visual information associated with thedistance and thickness is then combined with the visual image of theinstrument and tissue for presentation to the surgeon.

FIG. 5 provides a block diagram representing selected steps of a fourthembodiment of the invention that is similar to the second embodiment ofthe invention with the exception that the selected information about theposition (e.g. location and/or orientation) of the working end of theinstrument is tracked and supplied to the distance analysis block toallow improved (e.g. more efficient) analysis by allowing the analysisto be focused on or centered around a known or anticipated position ofthe working end of the instrument as determined from analysis of thevisual image or visual image information (e.g. known or estimated X & Ypositioning of the working end may lead to a reduction in the amount ofdiagnostic data that must be analyzed).

FIG. 6 provides a block diagram of selected substeps that may beinvolved in the distance analysis process and in particular provides anexample of how instrument tracking data of FIG. 5 may be supplied toblock 432 as a partial prior instrument location that is used in helpingdetermine a complete current position.

FIG. 7 provides a block diagram presenting selected steps of a fifthembodiment of the invention that is similar to the fourth embodiment ofthe invention with the exception that the instrument trackinginformation is provided as an input to the diagnostic scan block, asopposed to the distance analysis block so that it may be used infocusing the diagnostic scan to be made on only the selected regionsthat are necessary to derive the required separation distanceinformation.

FIG. 8 provides a block diagram representing selected steps of a sixthembodiment of the invention that combines the enhancements of the fourthand fifth embodiments such that tracked position information for theworking end is used to both limit the diagnostic scan region and theportion of the diagnostic scan data that will be analyzed to yield thedesired separation distance information.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

In some specific and focused embodiment of the invention, aphacoemulsification procedure is provided wherein the surgeon not onlyuses visual information provided within his/her field of view but alsouses instrument tip (i.e. a working end of a phacoemulsificationinstrument) to posterior capsule spacing (i.e. distance) informationthat is extracted from three-dimensional diagnostic scan data to aid indetermining whether continued cutting or scoring in a given locationwould risk damaging the capsule. In some embodiments, the distanceinformation is provided in the form of an auditory signal, in others asa visual signal, and in still others as a combination of the two. Insome embodiments the visual information is obtained directly (i.e. usingonly optical elements such as lenses, mirrors, filters, diffractiongratings, apertures, and the like between a source object having adiffuse surface reflection and the eye or eyes of the observer) while inothers it is obtained indirectly (i.e. coming from images that werecaptured by a camera or other image capture device and then displayed).

In other generalized embodiments of the invention, the proceduresassociation with a phacoemulsification process may be applied to othersurgical processes, mutatis mutandis. In such generalized embodimentsthe posterior portion of the capsule is analogous to a no fly-zone thatthe instrument tip should no penetrate while the crystalline lens isanalogous to target tissue that is to be removed or is at leastacceptable tor penetration. In some such generalized embodiments, thetarget tissue may be a tumor that is to be removed while the posteriorportion of the capsule represents healthy tissue or bounding tissue thatis not to be damaged during removal of the tumor.

A generalized phacoemulsification procedure, includes (a) forming atleast one opening in the eye to provide access to the anterior portionof the lens capsule; (b) forming an opening in the anterior region of alens capsule containing a lens to be removed; (c) inserting a workingend of a phacoemulsification instrument through the opening in theanterior region of the lens capsule; and (d) operating thephacoemulsification to remove the crystalline lens or to make one ormore trenches in the lens so that the lens may be spilt into one or moresmaller pieces which may then be removed.

As used herein, in generalized embodiments, anterior and posterior may,respectively, refer to the front (forward portion) of an organ or bodyregion and the rear (or back) portion of an organ or body region butthey may more generally refer to the front or back of a structure basedon an access direction with the anterior portion being the portion firstaccessed while the posterior portion is that portion which requires morepenetration to access. When confusion is possible, these terms may bereplaced with proximal and distal, respectively.

According to a first specific embodiment of the invention, improvementsto step (d) of this generalized procedures of a phacoemulisificationprocess are provided wherein step (d) includes (1) obtaining diagnosticscan data for the lens, the posterior portion of the capsule and theworking end of the phacoemulsification instrument; (2) analyzing thediagnostic scan data to obtain a separation distance between the workingend of the phacoemulsification instrument and the posterior region ofthe capsule; and (3) operating the phacoemulsification instrument whiledirectly or indirectly viewing the lens and the working end of thephacoemulsification instrument and while receiving separation distanceinformation resulting from the analysis of the diagnostic scan data andcontrolling the operation of the instrument based, at least in part, onthe separation distance information received, wherein during the courseof the operating of the phacoemulsification instrument, the obtaining ofdiagnostic scan data, the analyzing of the data, and the obtaining ofseparation distance information occurs a plurality of times.

FIG. 1 provides a block diagram representing selected elements of animproved surgical procedure (e.g., an improved phacoemulsificationprocedure) according to a first generalized and specific embodiment ofthe invention that focuses on enhancements to using a surgicalinstrument (e.g. a phacoemulsification instrument) to remove tissue(e.g. the crystalline lens of the eye) from an anterior surface toward aposterior surface which includes not only the use of visual images ofthe surgical field of view that is available to the surgeon but also ofrepresentations of separation distances of a working end of the surgicalinstrument (e.g. phacoemulsification instrument) relative to a posteriorboundary or portion of the tissue to be removed (e.g. relative to ananterior surface of the back wall of the capsule which borders theposterior surface of the lens), wherein the separation distance data isextracted from three-dimensional diagnostic scan data.

Element 102 of FIG. 1 calls for (1) a surgical instrument 102 (e.g.phacoemulsification instrument) to be viewed 111, by a surgeon 181, (2)the surgical instrument to interact with tissue 101 which is alsosubject to viewing 111, and (3) subjecting a combination of the surgicalinstrument 102 and tissue 101 to a diagnostic scan 121 (e.g. a selectedthree-dimensional scan). The diagnostic scan information is thenanalyzed to provide distance information 131 (e.g. distance informationbetween a working end of the instrument and a posterior boundary of thelens tissue, e.g. an anterior surface of the posterior portion of thecapsule bounding the lens) and the distance information is rendered 141into a form appropriate (e.g. visual or auditory) for use by thesurgeon. A combination of the visual image 111 of the instrument andtissue with the distance information 141 Is then used by the surgeon infurther operating the instrument 151 with the process looping baskthrough these information gathering elements/steps to provide updatedvisual images and distance, i.e. gap or separation, information thatkeeps the surgeon better informed of a current surgical progress or atleast instrument position relative to the tissue so as to minimizeinadvertent excessive penetrations of the working end of the instrumentbeyond a desired boundary region while simultaneously helping ensurethat target tissue is at least penetrated to a sufficient or adequatedepth into the target tissue to provide an intended surgical result.

Numerous variations of the first embodiment are possible. Some of thosepossibilities are set forth in FIGS. 2A-2C which provide examples ofvarious alternatives that may form part of the procedure of the firstembodiment, such as alternative diagnostic scan data types (FIG. 2A),rendering alternatives (FIG. 2B), and distance calculations includingoptional uses of previously known instrument locations (e.g. working endlocations that were obtained from previously analyzed diagnostic data)and/or capsule locations (FIG. 2C).

Variations of the first embodiment may obtain scan data form a varietysources and may obtain that data in a variety of forms. For example FIG.2A provides several alternative types of diagnostic scans 121 that maybe performed during a given surgery. In different types of surgeriesdifferent types of scans may be preferred due to different abilities todistinguish different tissue types, different resolutions available,different scanning speeds, different scanning logistics that areapplicability to different surgical circumstances, and the like. Inparticular, FIG. 2A indicates for example scan types that the used: anOCT scan 121-1, an MRI scan 121-2, a UBM scan 121-3, and/or anultrasonic scan 121-4. It is understood by those of skill in the artthat other scan types may also be used in some alternative embodiments.

Variations of the first embodiment may provide and/or render distance,information into a variety of forms. FIG. 2B provides two examples ofalternative rendering possibilities 141 for separation distanceinformation: (1) visual cues 141-1 and (2) audio cues 141-2. In somaembodiments one or the other of these alternatives may be used while inother embodiments both may be used together. Each form of cuing may takeon a variety of forms. Examples of visual cues include: (1) a series ofdiscrete pulse-like signals that can vary in temporal duration based ona predetermined set of distance ranges; (2) a series of discretepulse-like signals that can vary in temporal separation based on apredetermined set of distance ranges; (3) a signal whose pitch varies infrequency based on a predetermined set of distance ranges; and/or (4) asignal that enunciates or provides different sounds, selected from thegroup consisting of numbers, letters, words, or phrases based on apredetermined set of distance ranges.

Variations of the first embodiment may allow for visual images of thesurgical instrument and tissue being operated on to be provided to thesurgeon in a variety of different ways. For example visual images may bepresented to an eye piece of a microscope and/or provided via display orprojection onto an enlarged screen.

Visual cues, associated with the distance information may also beprovided in a variety of different ways as well. For example, such cuesmay be provided as color variations overlaid on the working end of thephacoemulsification instrument based on a predetermined set of distanceranges; as a geometric shape (e.g. a circular or elliptical image)centered on the working end of the phacoemulsification instrument basedon a predetermined set of distance ranges; as a shape located inproximity to the working end of the phacoemulsification instrumentselected from the group consisting of numbers, letters, words, phrases,or geometric shapes based on a predetermined set of distance ranges; asa color in combination with a shape located in proximity to the workingend of the phacoemulsification instrument selected from the groupconsisting of numbers, letters, words, phrases, or geometric shapesbased on a predetermined set of distance ranges; as a tinting of aselected portion of the image within the field of view based on apredetermined set of distance ranges; as a shape located within thefield of view selected from the group consisting of numbers, letters,words, phrases, or geometric shapes based on a predetermined set ofdistance ranges; as an intensity modulation of a portion of the visualsignal within a field of view based on a predetermined set of distanceranges; as a flashing signal; and/or as a flashing icon whose size,color, flash rate, or the like may be made to vary with distance. Inother embodiment variations, the visual cue may take the form of aseparately presented or overlaid 3-D view, 3-D sectional view, a 2-Dcut-end view, or 2-D cut side view showing the actual depth of removedmaterial and/or thickness of remaining material along with instrumentworking end position information, with or without other indications ofdistance

In some embodiment variations, augmented reality techniques, includingmarkerless tracking methods, may be used to display overlaid orcomposite images containing both a substantially real time image of thesurgical area along with enhanced images depicting relevant informationextracted from one or more 3-D scans of the surgical region so thatenhanced information may be provided to a surgeon. Such augmentedrealty, image overlaying, and markerless tracking methods are describedin a number of the articles and patent applications referenced herein,which are each incorporated herein by reference. The creation ofcomposite images may be done electronically or optically. The creationof composite images may use feedback of actual composite images toprovide enhanced or improved overlaying of component images.

Variations of the first embodiment may allow visual image updates to beprovided at different rates. For example they may be provided at a rateof several times per second or less or at a rate of 20 times per secondor more. Diagnostic scan data may also be updated at different rates.For example they may be updated once every ten seconds or less, at arate of several times per second or more, or somewhere in between.Alternative diagnostic scan data may be updated upon triggering by anoperator/surgeon. In some embodiments, visual image (i.e. surgical areavisual images) and diagnostic scan data may be presented at similarrefresh rates and synchronized phases with or without an intentionalphase shift. In still other embodiments image presentation updates ofone image component may be at an integer multiple of the other with orwithout the slower frequency component image being presented at the samerate as the higher frequency component.

Variations of the first embodiment may allow identification of theposterior boundary region to be made in a variety of different ways. Thediagnostic scan data, for example, may be analyzed using intensitygradient based techniques.

Variations of the first embodiment allow for distance analysis to beperformed in different ways and scan data to be used in a variety ofways. FIG. 2C provides an example of one such variation wherein a priorsurgical instrument location 132 may be used in finding (e.g. focusing asearch to find) a current surgical instrument location 133 that may inturn be saved as the prior instrument location 132 for a nextdetermination and is also used, in determining a distance 136 that isthe output of block 131′ (i.e. a possible variation of block 131 of FIG.1). Similarly, a prior location 135 of a posterior boundary (e.g. ananterior surface of a posterior capsule relative to a lens that is thetarget tissue) may be used in locating (e.g. focusing a search to find)a current position 134 of the posterior boundary, which current position135 may be used along with the current position 133 of the surgicalinstrument to determine the distance 136. In some variations, priorlocation of neither of the surgical instrument location nor the priorlocation of the boundary will be used to make the distance termination,only the prior location of one of the boundary or the instrumentlocation may be used in finding a current location, or in still othervariations both may be used.

FIG. 3 provides a block diagram representing selected steps of a secondembodiment of the invention that is similar to the first embodiment ofthe invention with the exception that rendered information takes theform of a visual representation that is overlaid with real visual imagesthat are presented to the surgeon.

Like elements between FIGS. 1 and 3 are labeled with like referencenumerals with the exception that the elements of FIG. 3 use the 200series while elements in FIG. 1 used the 100 series, Element 241 callsfor the rendering to be in visual form which is combined with the visualimage 211 of the surgical instrument 202 and tissue 201 beforepresentation to the surgeon. The combining or overlaying of these visualimages may occur optically as described in incorporated U.S. patentapplication Ser. No. 13/164,671 or electronically while the imagesremain in a data form. The overlaying may occur using markerlesstracking algorithms with or without electronic or optical feedbackallowing optimization of image registration. The rendered visual imageof the distance data for in a phacoemulsification procedure may take avariety forms such as by identifying the posterior capsule with a planethat is parallel to the XY plane and defining the plane as having afirst Z value, determining a second Z-value corresponding to the workingend of the instrument, and determining the difference of the first andsecond Z-values; by defining a geometric solid (e.g. a sphere) of adesired but small dimension (e.g. radius) that is centered on theworking end of the instrument, and comparing the geometric solid to theidentified posterior capsule position to determine if an intersectionexists, if not, increasing the dimension by a desired incrementalresolution step and repeating the intersection comparison, andcontinuing iterations until an intersection is determined whereby aseparation distance is determined to have a value somewhere between theimmediately preceding dimension and the dimension that resulted inintersection; and/or by creating progressively offset capsule surfacerepresentations, where each offset representation has an incrementalstep size, until the working end is intersected and then use the countof the number of steps and their respective spacings, with or withouttaking into consideration the last step, to determine the separationdistance.

FIG. 4 provides a block diagram representing selected steps of a thirdembodiment of the invention that is similar to the second embodiment ofthe invention with the exception that in addition to the diagnostic scandata being used to provide distance information concerning theseparation of a working end of the instrument and the posterior surface,the diagnostic scan data is also used to provide information concerningremaining thickness of material that is located between the working endof the instrument and the posterior surface, which thickness may be lessthan the distance when some of the intervening material has already beenremoved, visual information associated with the distance and thethickness is then combined with the visual image of the instrument andtissue for presentation to the surgeon.

As with FIG. 3 like elements between FIGS. 4 and 3 are identified withlike reference numerals with the exception that the reference numeralsof FIG. 4 are presented in the 300 series as opposed to the 200 series.

As noted above, in addition to the diagnostic scan data being used todetermine distance information 331, the scan data is used to determineremaining thickness as set forth in block 371. This second determinationmay be made in a variety of different ways. For example it may be basedon the scan having sufficient ability to detect not only the instrumenttip and the boundary between the target tissue and the anterior surfaceof an underlying posterior tissue) but also a boundary between ananterior surface of the target tissue that is located below and possiblyspaced from the working surface of the instrument. In alternativevariations, the thickness may be set to a previously calculated valuebased on a previously attained and determined distance of the instrumenttip from the posterior surface of the target issue (in the same XYlocation) that is less than the present distance under the assumptionsthat the distance is measured in a Z-direction and that any previouslyattained smaller distance necessarily dictates the previous removal ofunderlying tissue. The rendered distance information 341 and renderedthickness information 372 are overlaid 361 with the visual image 311.Blocks 341 and 372 may be providing either visual images or datarepresentative such visual images. As noted with regard to FIG. 3 theoverlaying may occur optically, electronically, or via a combination ofthe two (e.g. two images overlaid electronically and the combinationoverlaid optically with the third or two images overlaid optically, thenthe combination captured electronically, and subsequently electronicallyoverlaid with the third. As noted with the second embodiment, theoverlaying may or may not involve optical or electronic feedback toprovide for improved overlaying of the images with success updating ofcomponent or composite image frames.

FIG. 5 provides a block diagram representing selected steps of a fourthembodiment of the invention that is similar to the second embodiment ofthe invention with the exception that the selected information about theposition (e.g. location and/or orientation) of the working end of theinstrument is tracked and supplied to the distance analysis block toallow improved (e.g. more efficient) analysis by allowing the analysisto be focused on or centered around a known or anticipated position ofthe working end of the instrument as determined from analysis of thevisual image or visual image information (e.g. known or estimated X & Ypositioning of the working end may lead to a reduction in the amount ofdiagnostic data that must be analyzed).

Like elements of FIG. 5 as compared to FIG. 2 are labeled with likereference numeral as those of FIG. 2 with the exception that theelements of FIG. 5 use the 400 series of numerals as opposed to the 200series. Element 481 is added between element 411 and 431 so thatinstrument working end information (position and possibly orientation)can be at least partially determined and provided, along with the scaninformation from 421, to the distance gap analysis block 431 andthereafter the distance information, like in FIG. 2, is rendered perblock 441 and provided to block 461 for overlaying. In some embodimentvariations, visual image updates will occur more often than diagnosticscan up-dates. The instrument working end information associated withblock 481 may be derived from the most current visual image presented toblock 461 or it may be from visual image information that is relativelycurrent but not necessarily from the most recent visual image update.

FIG. 6 provides a block diagram of selected substeps that may beinvolved in the distance analysis process and in particular provides anexample of how instrument tracking data of FIG. 5 may be supplied toblock 432 as a partial prior instrument location that is used in helpingdetermine the complete current position.

In the variation of FIG. 6, surgical instrument tracking information(block 481 of FIG. 5) and diagnostic scan information (block 421 of FIG.5) are input to block 431′, which is an expanded variation of block 431of FIG. 5, with distance information 436 supplied to line informationrendering block 441 of FIG. 5, in the venation of FIG. 6 the instrumenttracking information extracted from the visual image information ofblock 411 is supplied to block 432 as partial prior instrument locationinformation and then passed on to block 433 for determination ofsurgical instrument location. Diagnostic scan information is provided toblock 433 as well so that both inputs may be used in determining thesurgical instrument location. The input from block 432 may allow lessexamination and analysis of the diagnostic scan data to identify thesurgical instrument location. Diagnostic scan data is also passed ontoblock 434 for use in locating the posterior boundary of the targettissue (e.g. anterior surface of the posterior portion of the capsule).Block 434 may also make use of prior saved posterior boundary locationinformation in determining new posterior boundary location and the newposterior boundary location may be saved to the prior boundary locationblock for subsequent use. The use of prior posterior boundary locationinformation, may allow less examination and analysis of the diagnosticscan data to identify the current posterior boundary location. The newposterior target tissue boundary location from block 434 and surgicalinstrument location from block 433 are used together to determine aseparation distance by block 436 torn which the output of block 431′ istaken.

FIG. 7 provides a block diagram representing selected steps of a fifthembodiment of the invention that is similar to the fourth embodiment ofthe invention with the exception that the instrument trackinginformation is provided as an input to the diagnostic scan block, asopposed to the distance analysis block so that it may be used infocusing the next diagnostic scan onto only the selected regions thatare necessary to derive the required separation distance information.

Elements of FIG. 7 that are similar to elements of FIG. 5 are identifiedwith like reference numerals with the exception that reference numeralsuse the 500 series of numbers. In fact the only real difference betweenFIGS. 5 and is that the output of block 581 is feed into one of theinputs for block 521 as opposed to block 531. As with the informationassociated with block 481, the information associated with block 581 maybe the most recent visual image information or relatively currentinformation but not the most recent (e.g. it may take longer to performthe diagnostic scan than allowed by the refresh rate of the visualimages). The information supplied from block 581 to block 521 may beused to limit the effective diagnostic scan region and thus might aid inreducing scan time associated with gathering the scan data.

FIG. 8 provides a block diagram representing selected steps of a sixthembodiment of the invention that combines the enhancements of the fourthand fifth embodiments such that tracked position information for theworking end is used to both limit the diagnostic scan region and theportion of the diagnostic scan data that will be analyzed to yield thedesired separation distance information.

Elements of FIG. 8 that are similar to elements of FIGS. 5 and 7 areidentified with like reference numerals with the exception thatreference numerals use the 600 series of numbers. In fact the only realdifference between FIGS. 8 relative to FIGS. 5 and 7 is that the outputof block 681 is feed into inputs for both block 621 and 631 as opposedto one or the other. As with the information associated with blocks 481and 581, the information associated with block 681 may be the mostrecent visual image information or relatively current information butnot the most recent (e.g. it may take longer to perform the diagnosticscan than allowed by the refresh rate of the visual images). Theinformation supplied from block 681 to block 621 (as in FIG. 7) may beused to limit the effective diagnostic scan region and thus might aid inreducing scan time associated with gathering the scan data while theinformation supplied from block 681 to block 631 (as in FIG. 5) may beused to reduce an amount of diagnostic data that must be analyzed toderive the distance information.

Numerous variations of the above noted embodiments are possible. Forexample, such variations may include modified embodiments resulting fromthe combination of selected elements from two or more of the sixpresented specific embodiments. Other modified embodiments can resultfrom combining features of the presented embodiments with selectedvariations presented above for the aspects of the invention.

Other embodiment may be directed to other medical procedures whereselected tissue is to be penetrated or removed (i.e. other than the lensin a phacoemulsification procedure) either to a desired depth below anoriginal anterior or proximal surface or to a desired thickness above aposterior or distal boundary of the target tissue (including to athickness of zero) and it is desired to determine, know, and make use ofcurrent distance information (i.e. between a working end of aninstrument and a more posterior boundary region during the tissueremoval process such that penetrations of the working end of theinstrument beyond the distal boundary are minimized or more preferablydo not occur at all). In other alternative embodiment the surgicalinstrument may be a diagnostic instrument and the procedure may be adiagnostic procedure (e.g. a biopsy procedure). In still otherembodiments, the surgical instrument may be a therapeutic or diagnosticinstrument that is intended not to necessarily remove significant tissuebut to locate a drug, therapeutic material, or diagnostic marker at oneor more precise positions relative to a boundary of the target tissuewherein the locating process may involve both visual image observationsand correlated distance information for precise placement of the drug,material or marker. Features of the previously presented embodiments andtheir variations, as well as features and variations set forth in theaspects of the invention may be combined with the other embodimentspresented herein to derive further embodiment variations andalternatives.

In some embodiments, a surgeon may not have direct control over asurgical instrument but instead the surgical instrument may be movedunder robotic control based on movements or other signals provided bythe surgeon (see blocks 151-651). In such embodiments, another opticalor auditory quing to the Surgeon might indicate whether or not amovement of the instrument actually occurred when commanded to make amovement by the surgeon and even whether the instrument movement was inan anticipated movement range.

Further Comments and Conclusions

The methods described herein may be used in combination with the methodsset forth in U.S. patent application Ser. No. 13/169,072, by Jean P.HUBSCHMAN et al., filed concurrently herewith, having Docket No.VSSP-007US-A, and entitled “Surgical Procedures Using Visual ImagesOverlaid with Visual Representations of Selected Three-DimensionalData”. Further information about overlaying multiple visual images(whether they be from physical sources or from computer rendered images)can be found in the various patents, patent applications, and non-patentpublications referenced herein (e.g. in the '671 application referencedherein above). These referenced patents, applications, and non-patentpublications are each incorporated herein by reference as if set forthin full herein.

In some embodiments, three-dimensional data (i.e. data from a diagnosticscan) is processed by a programmed computer to generate a visualrepresentation of the three-dimensional data thereafter the visualrepresentation is positioned and oriented with and overlaid on the imagedata of the eye so that the visual representation and image data may beviewed simultaneously. In some such embodiments of the invention, theoverlaying of the visual representation and image data of the eye occursvia the use of markerless tracking algorithms. Such markerless trackingalgorithms are known in the art and have been described previously. Seefor example the section entitled Markerless Tracking” in U.S. Pat. No.7,428,318; U.S. Patent Pub. No. 2005-1190972; and Comport et al. IEEETrans Visual Compo Graph. 12(4); 615-628 (2006). Additional teachingsconcerning the overlaying of multiple images can be found in U.S. patentapplication Ser. No. 13/164/671, filed Jun. 20, 2011 and entitled“Augmented Reality Methods and Systems Including Optical Merging of aPlurality of Component Optical Images”. Each of these referencedapplications patents and publications is hereby incorporated herein byreference) as if set forth in full herein.

As used herein surgeon may refer to an actual surgeon or other medicalpractitioner that is involved in performing a procedure of interest.Diagnostic scan means medical scans that are not simply visible lightimages of the eye taken with one or more conventional cameras (digital,video, etc). Visual image means one or more images viewed directly by asurgeon with only optical element extending from the source (e.g. aobject with a diffuse reflective surface) or indirectly by a surgeonwith an intermediate electronic capture and visual reproduction fromelectronic data between the surgeon and the source.

Though various portions of this specification have been provided withheaders, it is not intended that the headers be used to limit theapplication of teachings found in one portion of the specification fromapplying to other portions of the specification. For example, it shouldbe understood that alternatives acknowledged in association with oneembodiment, am intended to apply to all embodiments to the extent thatthe features of the different embodiments make such applicationfunctional and do not otherwise contradict or remove all benefits of theadopted embodiment. Various other embodiments of the present inventionexist. Some of these embodiments may be based on a combination of theteachings herein with various teachings incorporated herein byreference.

In view of the teachings herein, many further embodiments, alternativesin design and uses of the embodiments of the instant invention will beapparent to those of skill in the art. As such, it is not intended thatthe invention be limited to the particular illustrative embodiments,alternatives, and uses described above but instead that it be solelylimited by the claims presented hereafter.

We claim:
 1. A method for an improved phacoemulsification procedure,comprising: providing a phacoemulsification instrument including adistal working end configured to be inserted through an opening in theanterior region of an eye's lens capsule; processing diagnostic scandata for at least a portion of the lens capsule and the working end ofthe phacoemulsification instrument; providing a signal corresponding toa calculated separation distance information from an analysis of thediagnostic scan data and the distal working end of thephacoemulsification instrument during the course of thephacoemulsification procedure, wherein during the course of thephacoemulsification procedure, the diagnostic scan data is undated toprovide the calculated separation signal in real time.
 2. The method ofclaim 1, wherein the portion of the capsule from which at least some ofthe diagnostic scan data is obtained has a relatively planar centralregion which defines an XY plane from which a Z-axis extends toward theanterior portions of the eye, and wherein the separation distance ismeasured as a distance between the working end and the capsule along aline that is substantially parallel to the Z-axis.
 3. The method ofclaim 2, additionally comprising: analyzing the diagnostic scan data toprovide thickness information between an anterior surface of the lenscapsule and the portion of the capsule along lines substantiallyparallel to Z-axis for a plurality of XY locations.
 4. The method ofclaim 3, wherein the thickness information is provided as a visualrepresentation overlaid with the visual image being viewed.
 5. Themethod of claim 1, additionally comprising: overlaying a visualrepresentation of selected diagnostic scan information with visualimages being viewed by the surgeon.
 6. The method of claim 5,additionally comprising: updating the overlayed visual representation aplurality of times per second.
 7. The method of claim 6, wherein theupdating is done at a rate of about at least 20 times per second.
 8. Themethod of claim 5, wherein the overlaying is updated with each update ofcaptured visual image data that is displayed to the surgeon.
 9. Themethod of claim 5, additionally comprising: aligning the overlaid visualrepresentation and a visual image with one another using markerlesstracking methods.
 10. The method of claim 1, wherein the diagnostic scandata comprises one or more of data from an OCT, an MRI, an UBM, and anultrasound.
 11. The method of claim 1, wherein the separation distanceinformation is an auditory signal comprising one or more of: a series ofdiscrete pulse-like signals that can vary in temporal duration based ona predetermined set of distance ranges, a series of discrete pulse-likesignals that can vary in temporal separation based on a predeterminedset of distance ranges, a signal whose pitch varies in frequency basedon a predetermined set of distance ranges, and a signal that enunciatesdifferent sounds, selected from the group consisting of numbers,letters, words, or phrases based on a predetermined set of distanceranges.
 12. A medical procedure for penetrating, or removing targettissue, to a desired thickness from a posterior or distal boundary ofthe target tissue without penetrating the boundary with a working end ofa surgical instrument, the procedure comprising: forming at least oneopening in a covering tissue in proximity to the anterior surface of thetarget tissue to provide access to said anterior surface of the targettissue; inserting a working end of surgical instrument through theopening in the cover tissue to contact the target tissue; obtainingdiagnostic scan data for the target tissue, the posterior boundary, andthe working end of the surgical instrument; analyzing the diagnosticscan data to obtain a separation distance between the working end of thesurgical instrument and the posterior boundary region; and operating thesurgical instrument while viewing the target tissue, the working end ofthe surgical instrument and while receiving separation distanceinformation from the analysis of the diagnostic scan data, whereinduring the course of the procedure, the diagnostic scan data, theanalysis of the data, and the receiving of the separation distanceinformation are updated a plurality of times.
 13. The procedure of claim12, wherein the target tissue from which at least some of the diagnosticscan data is obtained has a relatively planar central region whichdefines an XY plane from which a Z-axis extends toward the anteriorsurface, and wherein the separation distance is measured as a distancebetween the working end and the target tissue along a line that issubstantially parallel to the Z-axis.
 14. The procedure of claim 13,additionally comprising: analyzing foe diagnostic scan data to providethickness information between the anterior surface of the target tissueand the posterior boundary along lines substantially parallel to Z-axisfor a plurality of XY locations.
 15. The procedure of claim 12, whereinthe thickness information is provided as a visual representationoverlaid with the visual image being viewed by a surgeon.
 16. Theprocedure of claim 12, additionally comprising: overlaying a visualrepresentation of selected diagnostic scan information with visualimages being viewed by a surgeon.
 17. The procedure of claim 16,additionally comprising: aligning the overlaid visual representation anda visual image with one another using markerless tracking methods. 18.The procedure of claim 12, wherein the diagnostic scan data comprisesone or more of data from an OCT, an MRI an UBM, and an ultrasound. 19.The procedure of claim 12, wherein surgical instrument comprises aninstrument selected from the group consisting of (1) a needle, (2) aprobe, (3) forceps, (4) a clamp, (5) scissors, (6) a knife, (7) aspreader, (8) a retractor, (9) tweezers, (10) an delivery cannula, (11)an aspirating cannula, (12) a cystotome, (13) a hydrodissector, (14) ahook, (15) a phaco chopper (16) a polisher, (17) a scrapper, (18) atissue extraction tool, and (19) a deposition tool.
 20. The procedure ofclaim 12, wherein the removed tissue includes one or more of a tumor, acrystalized lens, and a path blockage.